The disclosed technology relates to phosphites which may be oligomeric or polymeric materials, and their use in lubricant formulations, including greases, hydraulic fluids, turbine oils, circulating oils, industrial gearbox lubricants, and other applications.
Phosphorus esters of various types are well known for their use as lubricant additives. For example, U.S. Publication 2013/0079264, Tipton et al., Mar. 28, 2013, discloses a polymeric phosphorus ester comprising the condensation product of a monomeric phosphorus acid or an ester thereof with a diol, wherein the two hydroxy groups of the diol are separated by a chain of 4 to about 100 carbon atoms. An appropriately small amount of diol material having 2 or 3 atoms separating the hydroxy groups may be employed, provided that it does not substantially interfere with the polymer formation. Examples are compared from 1,6-hexanediol, 1,4-butanediol, diethylene glycol, or triethylene glycol. The polymeric phosphorus ester contains at least three phosphorus-containing monomer units.
U.S. Pat. No. 6,730,640, Sowerby et al., May 4, 2004, discloses a method for lubricating a continuously variable transmission. The lubricant is a fluid composition which comprises an oil of lubricating viscosity and an oil-soluble zinc salt, which may be a zinc hydrocarbyl phosphate. The zinc hydrocarbyl phosphate can be prepared by reacting phosphorus acid or anhydride with an alcohol, followed by neutralization with a zinc base. The alcohols may be monohydric alcohols, or polyhydric alcohols such as alkylene polyols such as ethylene glycols, including di-, tri- and tetraethylene glycols; propylene glycols, including di-, tri- and tetrapropylene glycols; glycerol; and the like. Additional additives may also be present, such as other friction modifiers and phosphorus-containing antioxidants.
U.S. Pat. No. 4,557,845, Horodysky et al., Dec. 10, 1985, discloses products of reaction between a 2-hydroxyalkylalkylamine or certain higher oxylated members, and a dihydrocarbyl phosphite as friction reducers and fuel reducing additives for internal combustion engines when such products are compounded with lubricant and liquid fuels. Among the reaction products are compounds such as
where R is a C6 to C30 hydrocarbyl group.
U.S. Pat. No. 5,773,392, Romanelli et al, Jun. 30, 1998, discloses an oil-soluble complex of an oil-insoluble phosphorus-containing acid and an alcohol. In certain examples, phosphorous acid is reacted with octylthioethanol and thiobisethanol. The complex is a useful antiwear additive.
U.S. Pat. No. 3,228,998, Fierce et al., Jan. 11, 1966, discloses liquid polyphosphate esters which may be useful as functional fluids. The general formula of the esters is

U.S. Pat. No. 3,328,360, Rozanski et al., Jun. 27, 1967, discloses polymers containing phosphorus, by reacting a mixture of direactive material and P4S10. Suitable direactive materials include, e.g., 1,10-decanediol. Derivatives of the phosphomers are generally useful as lubricant additives.
U.S. Pat. No. 5,544,744, Bloch et al., Aug. 22, 1995, discloses antiwear and antioxidant additives for use in lubricating oils. The additive is the reaction product of a phosphating agent and a thioalcohol. The alcohols may be represented by A-OH or OH—B—OH.
U.S. Pat. No. 4,549,976, Horodysky et al., Oct. 29, 1985, discloses lubricants and liquid fuel compositions containing a phosphorus oxyhalide vicinal diol reaction product. Examples show a phosphate ester of 1,2-mixed pentadecanediol-octadecanediol.
GB 1 146 379, Melle-Bezons, Mar. 26, 1969, discloses a transmission fluid using isopropylidene-bis[4-(nonylphenyl-decyl-phosphite)-cyclohexyl] as the antioxidant.
U.S. Pat. No. 4,298,481, Clarke, Nov. 3, 1981, discloses high temperature grease composition which contains a load bearing component. Useful load-bearing additives include polyphosphates including those of the structure(R1O)(R2O)P—OR3O——O—P(OR4)—OR5O—n—P(OR6)(OR7)[sic]R3 and R5 are polyalkylene glycol, alkylidene bisphenol, hydrogenated alkylidene bisphenol, or ring-halogenated alkylidene bisphenol from which the two terminal hydrogens have been removed; n is an integer in the range of 1 to 18.
U.S. Pat. No. 4,704,218, Horodysky et al., Nov. 3, 1987, discloses the reaction products of long chain vicinal diols containing at least 10 carbon atoms and one or more sulfur atoms in the chain, with a dihydrocarbyl hydrogen phosphate containing 1 to 6 carbon atoms in each hydrocarbyl group, as effective friction-reducing antiwear additives in lubricating oils, greases and fuels.
U.S. Pat. No. 6,103,673, Sumiejski et al., Aug. 15, 2000, discloses compositions containing friction modifiers for continuously variable transmissions, which include at least 0.1 percent by weight of at least one phosphorus compound. The phosphorus compound can be a phosphorus acid or ester of the formula (R1X)(R2X)P(X)nXmR3 where R1, R2, and R3 are hydrogen or hydrocarbyl groups. R1 and R2 groups can comprise a mixture of hydrocarbyl groups derived from commercial alcohols, examples being monohydric alcohols.
Mechanical devices such as industrial gearboxes and hydraulic fluid systems present highly challenging technological problems and solutions for satisfying the multiple and often conflicting lubricating and power transmitting requirements
Low molecular weight phosphites such as dialkyl (e.g., dibutyl) phosphites (sometime referred to as dialkyl hydrogen phosphites), notwithstanding their known performance benefits when used in various lubricants, may exhibit certain problems. For instance, they may absorb into elastomeric seals, leading to degradation of the seal material. They may also interact with sulfur-containing materials within a lubricant to give rise to objectionable odor. Materials of the technology disclosed herein may provide one or more of improved anti-wear performance, reduced deposit formation, or improved seal compatibility, when used to lubricate a mechanical device.